With a much older version of HWInfo32, the CPU Die read around -35 degrees (yes, minus)

I think I read somewhere that this MB/CPU combo reports the overhead and not the actual temp, hence the minus. Just wonder if the latest version subtracts the temp reading from the max to generate the CPU Die temp?

You're right, the CPU Die temperature under the QST sensor is usually reported as an offset from maximum temperature. So this is most probably not properly interpreted by HWiNFO.
Please attach the HWiNFO Debug File with sensor data and I will check how to fix this.